Known actuating devices, most of which are pyrotechnic, act directly on the cushion body, and are supported by a tubular frame inside the cushion body itself.
The frame is formed in one piece, with the supporting rods projecting from the cushion body to connect the headrest to the seatback, and comprises a curved rod portion, normally formed by welding a number of tubular parts, each shaped to attach the specific actuating device employed.
While enabling the manufacture of lightweight headrests, the tubular frame is complicated and time-consuming to produce, and designed for a specific type of headrest and cushion body. This is mainly due to the supporting rods forming an extension of the frame inside the cushion body, and therefore an integral part of a single monolithic frame of a given type of headrest.
Moreover, the geometry of the cushion body and the way in which it is connected to the actuating device are determined by the characteristics and size of the actuating device, which means connection of the cushion body to the actuating device is often complicated and awkward, especially on account of the actuating device having to be connected to an inner surface of the cushion body.